Many industries, including the assembly processing, grocery and food processing industry, have designated their products with a bar code symbol consisting of a series of lines and spaces of varying widths. Different bar code readers and laser scanning systems have been developed to decode the symbol pattern to a multiple digit representation for inventory, production-tracking and check-out purposes.
Modern miniature laser scanners using the laser diode, have recently been proposed to provide a portable and integrable laser scanning head for reading the bar code symbols at the variable distance. Other bar code scanners (called CCD bar code scanner) using the Light Emitting Diodes (LEDs) source and Charge Coupled Devices (CCD) have been developed to provide the same facilities at a reading distance of zero (contact) up to one and half inches away and for a bar code width no longer than the window or housing width. The actual CCD bar code scanner does not provide the comfort of the laser scanner which allows to read the bar code symbols at the variable distance and greater than the window or housing width.